Weather-agile reconfigurable automatic target recognition system

ABSTRACT

Applicants&#39; ATR system is weather-agile because it is comprised of a primary target sensing means that is capable of surveilling the target scene in foul or fair weather, and a secondary target sensing means that is also capable of sensing targets in various weather. The primary and secondary sensing means communicate through a control center so that ultimately, among several weapons available, the most strategically located and equipped weapon is activated for the destruction of a selected target, given the weather. The control center accomplishes the communication by receiving the sensed target signature from the primary sensing means, processing the signature using database already resident in the center and transmitting the processed target signature to the weapon possessing the greatest potential for successfully destroying the target.

DEDICATORY CLAUSE

The invention described herein may be manufactured, used and licensed byor for the Government for governmental purposes without the payment tous of any royalties thereon.

BACKGROUND OF THE INVENTION

On many battlefields, well-known target signatures are distorted byreal-world effects, such as various and varying environmentalconditions. Further, new, heretofore-unknown targets emerge that need tobe defined. As a consequence, updates of a target acquisition orautomatic target recognition (ATR) knowledge base are and continue to bea necessity for autonomous precision strike weapons. Such autonomousprecision strike weapons utilize all possible target sensing meansexcept direct laser designation of the targets.

ATR systems that use some type of pattern recognition need some form ofknowledge or training database resident in the systems for properoperation. Since the performance of any ATR system is limited by thesetraining data and often even known targets are obscured by camouflageand other means, most real-world applications require some real-timeupdates (i.e. retraining) of the target knowledge database. Thisrequirement also holds true for any new mobile or fixed targets. This“real-time” retraining is referred to as rapid retraining or rapidtarget update.

In an ATR system, the typically required information for the patternrecognizer consists of target and background/clutter signatures in theelectromagnetic band of interest. The robustness of ATR performance isusually quantified by correct classification of targets in some form,such as recognition or identification and false alarms defined as eitherclutter or misclassifications. The best ATR for any specific systemapplication can be selected from known algorithms that are amenable torapid retraining and also appropriate for the timeline for the specificapplication at hand. To maintain the ATR robustness through rapid targetupdating, however, the ATR must have the flexibility to be reconfiguredin response to the target scene information provided by the surveillancemeans. Part of this updating process includes establishing metrics ofthe clutter in the target scene so that the criteria on ATR performancecan be established for the specific target environment.

In general, multiple simultaneous weapon engagements are desired toeliminate multiple targets in a very short period of time. The rapidretraining of multiple weapons is restricted by the limitations ofavailable and compatible sensors.

SUMMARY OF THE INVENTION

Applicants' ATR system is weather-agile because it is comprised of afirst target sensing means, either singular or plural, that is (are)capable of surveilling the target scene in foul or fair weather, and asecond target sensing means, comprised of a group of sensors. At leastone sensor from the group comprising the second target sensing means ismounted on one of several available weapons. These sensors can alsosense targets in either foul or fair weather. Applicants' ATR systemmakes it possible to use dissimilar sensors in surveillance and in theweapons, while not excluding the use of similar active or passivesensors when conditions allow.

The first and second sensing means communicate through a control centerso that ultimately, among the several weapons available, the moststrategically located (based on its trajectory relative to the selectedtarget) and equipped (relative to the weather) weapon is activated forthe destruction of a selected target. The control center accomplishesthe communication by receiving the sensed target signature from thefirst sensing means, processing the signature using database alreadyresident in the center and transmitting the processed target signatureto the weapon possessing the greatest potential for successfullydestroying the target.

DESCRIPTION OF THE DRAWING

FIG. 1 illustrates the Weather-Agile Reconfigurable ATR System havingmulti-spectral target sensing means on both the surveillance platformand the weapons.

FIG. 2 shows the Reconfigurable ATR system wherein both the surveillanceand weapon sensors are synthetic aperture radars (SAR's).

FIG. 3 shows the Reconfigurable ATR system wherein the primary targetsensor on the surveillance platform is a SAR and the secondary targetsensor on the weapon is a laser radar.

FIG. 4 shows the Reconfigurable ATR system wherein the primary targetsensor is a SAR and the secondary target sensor is an electro-opticalsensor.

FIG. 5 shows the Reconfigurable ATR system wherein both the surveillanceand weapon sensors are electro-optical sensors.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Refer now to the drawing wherein like numbers represent like parts ineach of the several figures, solid lines with arrowheads representsignal paths and dotted lines with arrowheads represent the weapontrajectory. With reference to the drawing, different combinations ofvarious types of primary and secondary sensing means are presented forchangeable climatic conditions.

FIG. 1 is a diagram of the Weather-Agile Reconfigurable ATR Systemhaving multi-spectral target sensing means on both the surveillanceplatform and on the weapons. The primary sensing means is multi-spectralsensor 101 mounted onto airborne surveillance platform 105 from which itsurveils target scene 109 through any kind of weather that may existbetween the platform and the target scene. From this surveillanceactivity, the multi-spectral sensor produces target signatureinformation that is descriptive of the type of target detected. Thistarget signature information is downlinked to control center 111, alsothrough any kind of weather condition.

The control center has therein pre-existing database which pertains to,among others, target spectra, terrain and material classification,topography, atmospheric correction for converting radiance toreflectance, the capabilities and limitations of the sensing means onthe available weaponry and the location of the weaponry. The controlcenter transmits this database, to the extent practical, to surveillanceplatform 105 to optimize the transfer between the primary sensing meansand the control center of the most useful information for rapidretraining.

Upon receipt of the target signature information, the control centerprocesses (reformats) the information to discover the type and locationof the detected target and selects, among available weapons 107, theparticular weapon that is most likely to succeed in destroying thedetected target. The likelihood of success is determined based on thelocation of the weapon, its predicted trajectory relative to thelocation of the target and the wepon's destructive capabilities. Theselected weapon confirms to the control center the receipt of theupdate. Thereafter, the weapon is launched toward the target. In theembodiment shown in FIG. 1, the suitability of secondary sensing means103 on the weapon for detection of the target through the weatherencompassing the trajectory is deemed irrelevant since it is amulti-spectral sensor capable of functioning in all weather conditions.

FIG. 2 shows the Reconfigurable ATR system wherein both the surveillanceand weapon sensors are synthetic aperture radars (SAR) 201 and 203,respectively. Such active sensors of the same type being used togetheroffers the highest potential for image matching of spatial features. IfSAR sensors having different resolutions (example: higher resolution onthe surveillance and lower resolution on the weapons) are used, thedifferent resolution images of the same scene can be fused using themethod taught by Mario Costantini et al. in their article “The Fusion ofDifferent Resolution SAR Images,” in the PROCEEDINGS OF THE IEEE, vol.85, No. 1, pages 139-146. By fusing, a better match between the sensorscan be achieved. Accordingly, the fusion techniques described in thearticle are incorporated herein.

The SAR-to-SAR configuration is particularly useful when both sensorsmust operate in foul weather because when the weather is poor,electro-optical sensors or hyperspectral sensors provide little or nocapability. In FIG. 2, SAR imagery is collected over target scene 109 infoul weather indicated by clouds 205. In addition to clouds, the foulweather can be fog or rain. The SAR image collected must include bothpotential targets, confusers and clutter so that eventually a high levelof precision strike can be performed with virtually zero false alarmsand avoid unintended targets. The collected SAR imagery is compressedand down-linked to the control center with the position coordinates ofthe potential targets or “regions of interest” and the position of thesurveillance platform relative to the available weapons. Upon receipt,the control center decompresses the imagery, performs coordinatetransformation for a specific weapon trajectory and performs thediscrimination and classification processes using syntheticdiscrimination function filter. From this is derived the target spatialinformation which is formatted to allow rapid retraining of weapons withsynthetic aperture radar 203. It is noted that in the future, thecontrol center itself may potentially be eliminated or bypassed and itsfunctionality placed either at first or second sensing means orpartitioned between the two. This direct communication between thesensing means would help minimize the latency and result in improvedtarget elimination timeline.

The target spatial information derived by the control center can also betransmitted to weapons with laser radar 301 or electro-optical orhyperspectral sensor 401, as illustrated in FIGS. 3 and 4, respectively,if the weather encompassing the selected weapon trajectory is fair. Amethod for fusing SAR and hyperspectral image data sets over the samearea is taught by Su May Hsu et al. in “SAR and HSI Data Fusion forCounter CC&D,” The Record of the IEEE 1999 Radar Conference, pages218-220. Therefore, the method of co-registering the images usingreferences to terrain features, as described in the Hsu article, isincorporated herein.

If the weather conditions allow, use of purely passive sensors such aselectro-optical sensors 501 and 401 is highly desirable because itminimizes the potential of alerting the targets during multiplesimultaneous weapon engagements. This is illustrated in FIG. 5.Substitution of the electro-optical sensors with hyperspectral sensorsmay afford the ability to detect specific materials used in a targetobject.

The embodiment, depicted in FIG. 1, utilizing multi-spectral sensorsboth on the surveillance platform and on the non-reusable weapons mayentail substantial costs. An alternative is to use simultaneously thecombinations of various types of primary (on the surveillance platform)and secondary (on the weapons) sensing means as described above withreference to FIGS. 2 through 5. Many surveillance platforms havingthereon various types of primary sensing means may be deployed, allcommunicating with a common control center. Likewise, many groups ofweapons can be positioned at various locations, each group in turncomprising multiple weapons having different secondary sensing means. Inthis way, great flexibility is built into the Weather-AgileReconfigurable ATR system to achieve the least wasteful and mostaccurate precision strikes against selected targets.

Although a particular embodiment and form of this invention has beenillustrated, it is apparent that various modifications and embodimentsof the invention may be made by those skilled in the art withoutdeparting from the scope and spirit of the foregoing disclosure.Accordingly, the scope of the invention should be limited only by theclaims appended hereto.

1. A Weather-Agile Automatic Target Recognition System for performing arapid target update, said system adapting to changing climaticconditions for maximum performance efficiency, said system comprising: aprimary multi-spectral target sensing means capable of sensing adiversity of targets in diverse climatic conditions and generatingtarget signature corresponding to said sensed target; a plurality ofweapons; a plurality of secondary multi-spectral target sensing means,one of said secondary sensing means being mounted on one of said weaponsand enabling said weapon to seek the sensed target in the extantclimatic condition, said primary and secondary sensing means cooperatingwith each other to destroy selected targets; and a control center havingtherein pre-existing target, weaponry and environmental databases, saidcenter positioned to communicate with said primary and secondarymulti-spectral target sensing means, said center receiving said targetsignature from said primary sensing means and processing said signatureusing said preexisting databases prior to transmitting said processedsignature to said secondary sensing means residing on a weapon selectedas having the greatest potential to accomplish a successful destructionof the sensed target.
 2. A Weather-Agile Automatic Target RecognitionSystem for performing a rapid target update as set forth in claim 1,wherein said primary multi-spectral target sensing means is mounted onan airborne surveillance platform positioned to observe a target sceneand said control center transmits to said primary sensing means saidpre-existing databases to facilitate efficient surveillance by saidprimary sensing means.
 3. A Weather-Agile Automatic Target RecognitionSystem for performing a rapid target update, said system adapting tochanging climatic conditions for maximum performance efficiency, saidsystem comprising: a primary target sensing means mounted on an airbornesurveillance platform, said primary sensing means being capable ofsensing a diversity of targets in a given climatic condition andgenerating target signature corresponding to said sensed target; aplurality of weapons, said weapons each having an individual secondarytarget sensing means, said individual sensing means enabling saidweapons to seek the sensed target in the extant climatic condition, saidprimary and individual secondary sensing means cooperating with eachother to destroy selected targets; and a control center having thereinpre-existing target, weaponry and environmental databases, said centerpositioned to communicate with said primary and individual secondarysensing means, said center transmitting to said first sensing means saidpre-existing databases to facilitate effective surveillance by saidfirst sensing means, receiving from said primary sensing means saidtarget signature and processing said signature using said pre-existingdatabases to produce processed target signature, said centersubsequently transmitting said processed target signature to saidindividual sensing means residing on a weapon selected as having thegreatest potential to accomplish a successful destruction of the sensedtarget.
 4. A Weather-Agile Automatic Target Recognition System forperforming a rapid target update as set forth in claim 3, wherein saidprimary sensing means comprises a synthetic aperture radar for maximumtarget recognition in foul weather, and each individual secondarysensing means comprises a synthetic aperture radar for maximum targetrecognition and destruction in foul weather in response to saidprocessed target signature.
 5. A Weather-Agile Automatic TargetRecognition System for performing a rapid target update as set forth inclaim 3, wherein said primary sensing means comprises a syntheticaperture radar for maximum target recognition in foul weather, and eachindividual sensing means comprises a laser radar for maximum targetrecognition and destruction in fair weather in response to saidprocessed target signature.
 6. A Weather-Agile Automatic TargetRecognition System as set forth in claim 3, wherein said primary sensingmeans comprises a synthetic aperture radar for maximum targetrecognition in foul weather, and each individual sensing means comprisesan electro-optical sensor for maximum target recognition and destructionin fair weather in response to said processed target signature.
 7. AWeather-Agile Automatic Target Recognition System as set forth in claim3, wherein said primary sensing means comprises an electro-opticalsensor for target recognition in fair weather, and each individualsensing means comprises an electro-optical sensor for maximum targetrecognition and destruction in fair weather in response to saidprocessed target signature.
 8. A Reconfigurable Automatic TargetRecognition System for performing a rapid target update in changingclimatic conditions for maximum performance efficiency, said systemcomprising: a plurality of primary target sensing means; a plurality ofairborne surveillance platforms, each of said primary target sensingmeans being mounted onto one of said platforms such that there are nomore than one primary target sensing means on any one platform, each ofsaid primary target sensing means being capable of sensing a diversityof targets in a given climatic condition and generating target signaturecorresponding to said sensed target; a plurality of weapons, saidweapons each hosting an individual secondary target sensing means, saidindividual sensing means enabling its hosting weapon to seek the sensedtarget in the extant climatic condition, said primary and individualsecondary sensing means cooperating with each other to destroy selectedtargets; and a control center having therein pre-existing target,weaponry and environmental databases, said center positioned tocommunicate with said plural primary and individual secondary sensingmeans, said center receiving said target signature from one or more ofsaid primary sensing means and processing said signature using saidpre-existing databases prior to transmitting said processed targetsignature to said individual sensing means hosted in a weapon selectedas having the greatest potential to accomplish a precision destructionof the sensed target.
 9. A Reconfigurable Automatic Target RecognitionSystem for performing a rapid target update in changing climaticconditions as set forth in claim 8, wherein some of said primary targetsensing means are synthetic aperture radars and the others areelectro-optical sensors.
 10. A Reconfigurable Automatic TargetRecognition System as set forth in claim 9, wherein some of saidindividual secondary target sensing means hosted by said weapons, onesecondary target sensing means on one weapon, are synthetic apertureradars, some are laser radars and yet others are electro-opticalsensors.